What is the nictitating membrane in a frog

Wind energy is plentiful in regions with vast open spaces it is a non polluting renewable resource what could be an economic factor that makes the use of this resource less feasible then non renewable resource even in such regions

An ecologist is studying the effects that a population of predators is having on a population of a prey. he used data from the field to produce this graph. which conclusion can draw from the graph?

Predict the results of a two base insertion or deletion in a strand of dna that codes for a protien, how does this differ from a three base insertion or deletion?